Novel fluoroelastomers composed of tetrafluoroethylene and vinylidene fluoride oligomers synthesized in carbon dioxide for use in soft lithography to enable a platform for the fabrication of shape- and size-specific, monodisperse biomaterials Public Deposited

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  • March 21, 2019
Creator
  • Kelly, Jennifer Yvonne
    • Affiliation: College of Arts and Sciences, Department of Chemistry
Abstract
  • Fluorinated elastomers are materials with tremendous utility that have found use as minimally adhesive mold materials in soft lithography. The first objective of this research involved the synthesis of novel functional, fluorinated oligomers in supercritical carbon dioxide (scCO2) and the fabrication of the resulting fluorooligomers into solid elastomers using free radical crosslinking chemistry. Commercially available fluoroelastomers are typically synthesized in aqueous media using fluorinated surfactants or in non-aqueous conditions using fluorinated solvents. This research effort focused on the synthesis of low molecular weight oligomers consisting of tetrafluoroethylene (TFE) and vinylidene fluoride (VF2) with a cure site comonomer in scCO2 at low temperatures. Using CO2 as a polymerization medium allows for safe handling of TFE, is environmentally responsible by mitigating the typical generation of halogenated, organic, or aqueous waste, and circumvents the use of fluorinated surfactants as these copolymers are soluble in CO2. Investigations included characterizing the fluorinated oligomers and the solid elastomeric materials using NMR, DSC, TGA, GPC, IR, and via surface and mechanical property analysis. The second objective of this research included the use of fluoroelastomers as minimally adhesive mold materials in soft lithography applications using the Particle Replication In Non-wetting Templates (PRINT) technology for the fabrication of protein particles of discrete size and shape. Lyophilized protein particles are generally highly disperse in particle size, tend toward aggregation, and are often made through complicated processes. In attempts to engineer mono-disperse protein particles, the use of wet-milling, spray-freeze-drying, micro-emulsion, or super critical fluid methods have been reported. The PRINT process enables a gentle, facile route to mono-disperse particles composed of protein with and without cargo. This research objective included fabricating protein PRINT particles of varying sizes, shapes, and compositions (e.g., Abraxane, albumin, tranferrin, insulin, interferon-beta, hemoglobin, trypsin, horseradish peroxidase, and IgG). Several biophysical characterizations were performed to verify the protein structure was not significantly altered during the PRINT process, including SEM, FTIR, fluorescence microscopy, and CD. Furthermore, ELISA and enzymatic activity assays were performed to investigate biological integrity and function of all proteins. The PRINT technology was found to be a gentle method to create nanoparticles of biologically relevant proteins.
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  • In Copyright
Advisor
  • DeSimone, Joseph M.
Degree granting institution
  • University of North Carolina at Chapel Hill
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  • Open access